Hybrid View

Contact Information not shown in Mailbox

If I hover over an e-Mail Address in my inbox it should display all contact information like phone, company etc. in a pop-up window. So it does for contacts in GAL but not for contacts imported from csv. If I click "Add Contact" by hovering over an e-mail address this contact's info is also been shown.

Does anybody know if this is a bug or how to enable the imported contacts to be shown as intended by hovering over the email- Address?